Bingo. That is precisely correct.
But in the meantime, I have figured out a solution. It's not pretty or elegant, but it works. The solution was to simply disable networking in the Specialize phase like this:
<RunSynchronousCommand wcm:action="add">
<Description>Disable Networking</Description>
<Order>1</Order>
<Path>powershell.exe -Command "Get-NetAdapter | Disable-NetAdapter -Confirm:$false"</Path>
</RunSynchronousCommand>
The only thing remaining now is to run a command after Windows starts for the first time to enable networking like this:
powershell.exe -Command "Get-NetAdapter | Disable-NetAdapter -Confirm:$false"
The interesting thing is that I have never had a need to run anything after setup has completed, so I've never done this before, but I think that I am familiar with the procedure. I just need to test it. But in the very worst case I would simply need to go into Device Manager and enable the net adapter(s), but I think that I got this